Authors: Mike Bixenman, D.B.A, Debbie Carboni, Jason Chan Company: Kyzen Date Published: 5/14/2013
ICSR (Soldering and Reliability)
Abstract: Stencil printing capability is becoming more important as the range of component sizes assembled on a single board increases. Coupled with increased component density, solder paste sticking to the aperture sidewalls and bottom of the stencil can cause insufficient solder paste deposits and solder bridging. Yield improvement requires increased focus on stencil technology, printer capability, solder paste functionality and understencil cleaning. The wide range of required solder paste volume deposited on mixed technology assemblies is pushing traditional stencil design rules to their limit. There is a need for improved stencil, printing and materials technologies to increase the consistency of the deposit. Cleaning the underside of the stencil is a critical enabler to yield improvement. The purpose of this research is to study the wipe sequence, wipe frequency and wipe solvent(s) and how these factors interact to provide solder paste printing yield improvement.